Electric cooktops, particularly those with induction or solid disk elements, often cycle on and off when set to a low heat setting due to a technology called "pulse-width modulation" (PWM). This technology is used to control the power output and maintain a consistent temperature at lower settings. Here's how it works:
Power Control: Electric cooktops have a fixed maximum power output, typically measured in watts. When you lower the heat setting, the cooktop needs to reduce the amount of power supplied to the heating element to generate less heat.
Limitations of Continuous Lower Output: If the cooktop were to supply a constant, lower output to the heating element, it might not produce enough heat to maintain the desired temperature. The heating element requires a minimum amount of power to generate and sustain the heat needed for cooking.
Pulse-Width Modulation (PWM): To achieve lower heat settings while still providing sufficient power to the heating element, the cooktop uses PWM. Instead of providing a constant lower output, it cycles the power on and off at a high frequency.
Rapid Cycling: At low heat settings, the cooktop rapidly cycles the power on and off. The percentage of time that the power is on compared to the total cycle time is adjusted to control the average power delivered to the heating element.
Temperature Control: The PWM system continuously monitors the cookware's temperature by using built-in sensors. If the temperature drops below the desired level, the cooktop increases the percentage of time the power is on, providing more heat. Conversely, if the temperature rises above the desired level, the cooktop reduces the percentage of time the power is on to prevent overheating.
By using PWM, the electric cooktop can effectively control the power output and maintain a consistent temperature at lower settings, giving you more precise control over your cooking. This technology is also energy-efficient as it reduces power consumption when the lower heat output is needed, making it a common feature in modern electric cooktops.